Physical Sciences Grade 12 P2 Gauteng June 2024 QP (Eng)

Downloaded from hlayiso.com JUNE EXAMINATION GRADE 12 2024 PHYSICAL SCIENCES: CHEMISTRY (PAPER 2) TIME: 3 hours MARKS: 150 17 pages + 4 data sheets Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 2 (PAPER 2) GR12 0624 INSTRUCTIONS AND INFORMATION 1. This question paper consists of EIGHT questions. Answer ALL the questions in the ANSWER BOOK. 2. Start EACH question on a NEW page in the ANSWER BOOK. 3. Number the answers correctly according to the numbering system used in this question paper. 4. Leave ONE line open between two subquestions, e.g., between QUESTION 2.1 and QUESTION 2.2. 5. You may use a non-programmable calculator. 6. You may use appropriate mathematical instruments. 7. Show ALL formulae and substitutions in ALL calculations. 8. Round-off your FINAL numerical answers to a minimum of TWO decimal places. 9. Give brief discussions, et cetera where required. 10. You are advised to use the attached DATA SHEETS. 11. Write neatly and legibly. Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 3 (PAPER 2) GR12 0624 QUESTION 1: MULTIPLE-CHOICE QUESTIONS Various options are given as possible answers to the following questions. Each question has only ONE correct answer. Choose the answer and write only the letter (A – D) next to the question numbers (1.1 to 1.10) in the ANSWER BOOK, e.g. 1.11 E. 1.1 Consider the condensed structural formula below: CH3CH2CH2OH What is the name of the functional group? A Hydroxyl group B Carbonyl group C Formyl group D Carboxyl group (2) 1.2 Consider the compound below: Which of the following is the IUPAC name of this compound? A 2,2,4-trimethyl-5-ethylheptane B 4,6,6-trimethyl-3-ethylheptane C 5-ethyl-2,2,4-trimethylheptane D 3-ethyl-4,6,6-trimethylheptane (2) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 4 (PAPER 2) GR12 0624 1.3 Ethanal, ethanol, ethanoic acid, and ethane are compounds that are found in a laboratory. Arrange the compounds mentioned above in decreasing order of vapour pressure. A Ethanoic acid, ethanol, ethanal, ethane B Ethane, ethanal, ethanol, ethanoic acid C Ethanoic acid, ethanal, ethanol, ethane D Ethane, ethanol, ethanal, ethanoic acid (2) 1.4 Which of the following reaction types will be used to prepare ethene and propane from pentane under high temperatures and pressures? A Combustion B Esterification C Catalytic cracking D Thermal cracking (2) 1.5 The graph below represents the relationship between potential energy and course of reaction for a certain chemical reaction. Potential energy (kJ) Course of reaction The heat of reaction for the reverse reaction is: A 2 kJ B 4 kJ C -2 kJ D -5 kJ (2) 1.6 The equation below represents the decomposition of calcium carbonate. CaCO3(s) CaO(s) + CO2(g) Which of the following factors will NOT affect the initial rate of decomposition of calcium carbonate? A Increase in temperature B Using powdered calcium carbonate C Adding a catalyst D Increasing the mass of calcium carbonate (2) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 5 (PAPER 2) GR12 0624 1.7 The reaction represented by the equation below reaches equilibrium. Co(H2O) (aq) + 4Cℓ − (aq) ⇌ CoC (aq) + 6H2O(ℓ) ΔH > 0 pink blue Which of the following changes to the reaction mixture will change its colour from pink to blue? A Add a catalyst. B Place the reaction mixture in a container with cold water. C Add a few drops of concentrated hydrochloric acid to the reaction mixture. D Add water to the reaction mixture. (2) 1.8 The following hypothetical reaction is at equilibrium at 500 K: A2(g) + B(g) ⇌ A(g) + AB(g) The diagram below shows the molecules involved in this chemical equilibrium at 500 K. Key: =A and =B The temperature is decreased to 300 K. The diagram below represents the same equilibrium mixture at 300 K. Which of the following statements is CORRECT? A The forward reaction is exothermic. B The concentration of AB is lower at a lower temperature. C The forward reaction is endothermic. D The concentration of B is higher at a lower temperature. (2) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 6 (PAPER 2) GR12 0624 1.9 Which of the following is the CORRECT description for a 10 mol∙dm-3 hydrochloric acid solution? A Dilute strong acid B Dilute weak acid C Concentrated weak acid D Concentrated strong acid (2) 1.10 Consider the reaction represented by the following equation: 2Ag+(aq) + Cu(s) → 2Ag(s) + Cu2+(aq) Which of the following represents the oxidising agent in the above reaction? A Ag+ B Cu C Ag D Cu2+ (2) [20] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 7 (PAPER 2) GR12 0624 QUESTION 2 (Start on a new page.) A to H in the table below represents eight organic compounds. A B 2-methylbutan-2-ol C D Pentan-2-one CH3CH2COCH2CH3 E F Butan-2-ol Methyl propanoate G H Use the table above to answer the following questions. 2.1 Define the term homologous series. (2) 2.2 Consider the organic compound G. 2.2.1 Write down the homologous series to which this compound belongs. (1) 2.2.2 Write down the CONDENSED STRUCTURAL FORMULA. (1) 2.2.3 Write down the IUPAC name of the functional isomer of G. (2) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 8 (PAPER 2) GR12 0624 2.3 Write down the: 2.3.1 IUPAC name of compound H (3) 2.3.2 GENERAL FORMULA of the homologous series to which compound A belongs (1) 2.4 Write down the letter(s) of the compound(s) that represent(s): 2.4.1 The positional isomers (2) 2.4.2 An ester (1) 2.5 Consider the organic compound B. 2.5.1 Write down the STRUCTURAL FORMULA. (2) 2.5.2 Is compound B a PRIMARY, SECONDARY or TERTIARY alcohol? (1) 2.5.3 Explain the answer to QUESTION 2.5.2. (2) 2.6 Hydrocarbons are the principal constituents of petroleum and natural gas. A hydrocarbon consists of 81,82% carbon and 18,18% hydrogen. Calculate the empirical formula of this hydrocarbon. (4) [22] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 9 (PAPER 2) GR12 0624 QUESTION 3 (Start on a new page.) A group of learners decide to conduct an investigation to compare the boiling points of the first three haloalkanes, namely chloromethane, chloroethane and 1-chloropropane. The table below shows the results obtained from the investigation. COMPOUND IUPAC NAME BOILING POINT (°C) A chloromethane -24,2 B chloroethane 12,3 C 1-chloropropane 46,6 3.1 Define the term boiling point. (2) 3.2 Identify the: 3.2.1 Independent variable (1) 3.2.2 Dependent variable (1) 3.2.3 Controlled variable (1) 3.3 Write down a suitable investigative question. (2) 3.4 Chloromethane is highly flammable. Write down ONE precaution that should be taken when working with this substance in the laboratory. (1) 3.5 Which ONE of these substances (A, B, or C) has the lowest vapour pressure? Give a reason for the answer. (2) 3.6 The learners find 1-chlorobutane in the laboratory. How would the boiling point of 1-chlorobutane compare to that of 1-chloropropane? Write only HIGHER THAN, LOWER THAN or EQUAL TO. (1) 3.7 Explain the answer to QUESTION 3.6 by referring to the type of intermolecular forces, strength, and energy. (3) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 10 (PAPER 2) GR12 0624 3.8 The learners decide to do another investigation with compounds J and K. J K Butane Bromine water is used to distinguish between compounds J and K by adding it to each compound in two separate test tubes. The learners observe that one compound decolourises the bromine water immediately, while the other substance only reacts after placing the test tube in direct sunlight. Write down: 3.8.1 The letter (J or K) of the compound that will immediately decolourise the bromine water (1) 3.8.2 The reason that the other substance only reacts when placed in direct sunlight (1) 3.8.3 The MOLECULAR FORMULA of the organic product formed in the test tube containing compound J (2) 3.8.4 A balanced chemical equation when compound K undergoes complete combustion (3) [21] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 11 (PAPER 2) GR12 0624 QUESTION 4 (Start on a new page.) The flow diagram below shows three organic reactions, namely Reactions I, II and III. Various organic and inorganic products are formed as a result of these reactions. Pentane + HBr Compound C 2-bromopentane Compound B + Product A Use the flow diagram above to answer the following questions. 4.1 Define the term saturated compound. (2) 4.2 2-bromopentane undergoes hydrolysis. 4.2.1 Name the type of reaction represented in Reaction I. (1) 4.2.2 Name the inorganic product A that is formed in the reaction. (1) 4.2.3 Give ONE reaction condition. (1) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 12 (PAPER 2) GR12 0624 4.3 Consider compound B. 4.3.1 Write down the IUPAC name. (2) 4.3.2 Name the type of reaction represented in Reaction II. (1) 4.3.3 Write down the STRUCTURAL FORMULA of the major product C. (2) 4.3.4 Write down the CHEMICAL FORMULA of the inorganic product formed in Reaction II. (1) 4.4 Consider Reaction III. 4.4.1 Name the type of addition reaction. (1) 4.4.2 Give the CHEMICAL FORMULA of the catalyst needed for this reaction. (1) 4.5 Esterification is one of the most important reactions in both organic synthesis and the chemical industry. When making an ester, 60 g of propan-1-ol reacts with excess ethanoic acid which produces 90,78 g of an ester and water. The balanced chemical equation below shows the reaction that takes place. C3H8OH () + CH3COOH (aq) → C5H10O2 () + H2O () 4.5.1 Write down the STRUCTURAL FORMULA for the ester produced. (3) 4.5.2 Give the IUPAC name for the ester. (2) 4.5.3 Give the chemical name of the catalyst used. (1) 4.5.4 Calculate the percentage purity of propan-1-ol. (5) [24] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 13 (PAPER 2) GR12 0624 QUESTION 5 (Start on a new page.) A group of learners use the reaction between excess hydrochloric acid and magnesium ribbon to investigate one of the factors that influences the rate of a chemical reaction. The reaction that takes place is: Mg(s) + 2HC (aq) → MgC2 (aq) + H2(g) The learners follow the method shown below to conduct the investigation at room temperature. A diagram of the apparatus is given below. Method – Experiment 1: Step 1: Place a piece of magnesium ribbon in a conical flask and add 50 cm3 HC (aq) of known concentration. Step 2: Simultaneously start the stopwatch and close the flask with the rubber stopper containing the delivery tube. Step 3: Measure the volume of the H2(g) formed in time intervals of 20 seconds. Method – Experiment 2: Repeat steps 1 to 3 above, but use only 15 cm3 of the same HC (aq) diluted with 50 cm3 distilled water. Apparatus: gas syringe magnesium ribbon dilute hydrochloric acid 5.1 Define the term reaction rate. (2) 5.2 Write down a conclusion for this investigation. (2) 5.3 The concentration of the hydrochloric solution is 2 mol·dm-3. Calculate the concentration used in Experiment 2. (3) 5.4 Name TWO conditions that learners had to keep the same to ensure that this is a fair test. (2) Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 14 (PAPER 2) GR12 0624 After completing the investigation, the learners represented the results obtained during each experiment on the graph below. Graph of volume of hydrogen gas versus time 60 ● ● ● ● Experiment 1 ● ● 50 ● Experiment 2 ● 40 Volume of hydrogen gas (cm3) ● 30 ● 20 ● 10 0 0 20 40 60 80 100 120 140 Time (s) 5.5 Give a reason why the same volume of hydrogen gas is formed in both experiments. (1) 5.6 Write down the volume of hydrogen gas formed during the first minute in: 5.6.1 Experiment 1 (1) 5.6.2 Experiment 2 (1) 5.7 Which ONE of the experiments (Experiment 1 or Experiment 2) took place at a faster rate? Use the graph to explain the choice. (3) 5.8 Calculate the average reaction rate with respect to the magnesium, in g·s-1, in Experiment 1 if the molar volume at room temperature is 24 dm3. (5) [20] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 15 (PAPER 2) GR12 0624 QUESTION 6 (Start on a new page.) The reaction between steam and chlorine gas reaches equilibrium in a closed container according to the following balanced equation: 2H2O(g) + 2Cℓ2(g) ⇌ 4HCℓ(g) + O2(g) ΔH = +113 kJ 6.1 Is this reaction EXOTHERMIC or ENDOTHERMIC? Give a reason for the answer. (2) 6.2 The graphs below, not drawn to scale, show how the amount of products present in the container change with time at a specific temperature. The volume of the container is 5 dm3. 1,0 Amount of product (mol) 0,3 HCℓ(g) 0,1 O2(g) 0 t1 t2 t3 Time (minutes) 6.2.1 Which reaction is favoured? Choose from FORWARD or REVERSE? Give a reason for the answer. (2) 6.2.2 How do the rates of the forward and the reverse reactions compare at time t3? Write down only GREATER THAN, SMALLER THAN or EQUAL TO. (1) 6.2.3 Calculate the equilibrium constant (Kc) for this reaction at this temperature if there was initially 5 g of water and 5 g of chlorine. (9) 6.3 The pressure is NOW increased. How will this change affect the value of the equilibrium constant? Write down only INCREASE, DECREASE or REMAINS THE SAME. Give a reason for the answer (2) 6.4 The reaction is repeated with a catalyst. Draw a potential energy diagram of this reaction and indicate the non-catalysed reaction (B) and catalysed reaction (A) on the same graph. (4) [20] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 16 (PAPER 2) GR12 0624 QUESTION 7 (Start on a new page.) 7.1 Sulphuric acid is a diprotic acid. 7.1.1 Define the term ACID in terms of the Arrhenius theory. (2) 7.1.2 Give a reason why sulphuric acid is referred to as a diprotic acid. (1) 7.2 The hydrogen carbonate ion can act as both an acid and a base. It reacts with water according to the following balanced equation: HCO3- (aq) + H2O(ℓ) ⇌ H2CO3(aq) + OH-(aq) 7.2.1 Write down ONE word for the underlined phrase above. (1) 7.2.2 Copy the equation above and indicate the conjugate acid-base pairs. (2) 7.3 A laboratory assistant was asked to prepare a 2 500 cm3 solution of HC with a concentration of 0,25 mol·dm-3. The laboratory had a bottle of concentrated HC which had the following written on the label: Chemical: HC Density: 1,20 g·cm-3 % HC by mass in solution: 36% 7.3.1 Calculate the mass of HC contained in 2 500 cm3 of a 0,25 mol·dm-3 solution. (4) 7.3.2 50 cm3 of the 0,25 mol·dm-3 HC solution is used to neutralise 20 cm3 of a sodium carbonate (Na2CO3) solution. 2HC + Na2CO3 → 2NaC + H2O + CO2 Calculate the concentration of the carbonate solution. (4) 7.3.3 Name a suitable indicator that can be used for this titration. Give a reason for the answer. (2) [16] Please turn over

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 17 (PAPER 2) GR12 0624 QUESTION 8 (Start on a new page.) 8.1 A clean piece of copper (Cu) is placed in a solution of silver nitrate (AgNO3). The balanced net ionic equation is: Cu (s) + 2 Ag+ (aq) → Cu2+ (aq) + 2 Ag (s) 8.1.1 Define oxidation in terms of electron transfer. (2) 8.1.2 What type of reaction does copper (Cu) undergo in this equation? Choose from OXIDATION or REDUCTION. Explain the answer by referring to oxidation numbers. (3) 8.2 Sulphur dioxide gas (SO2) is bubbled into an acidified solution of potassium permanganate as shown in the diagram below. SO2 gas KMnO4 solution It is observed that the solution turns from purple to colourless due to the reduction of MnO ions to Mn2+ ions. During the reaction SO2 is oxidised to sulphate ions, SO . Determine the oxidation number of manganese, in the permanganate ion (MnO ). (2) [7] TOTAL: 150 END

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 18 (PAPER 2) GR12 0624 DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 2 (CHEMISTRY) GEGEWENS VIR FISIESE WETENSKAPPE GRAAD 12 VRAESTEL 2 (CHEMIE) TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES NAME/NAAM SYMBOL/SIMBOOL VALUE/WAARDE Standard pressure p 1,013 x 105 Pa Standaarddruk Molar gas volume at STP Vm 22,4 dm3∙mol-1 Molêre gasvolume by STD Standard temperature T 273 K Standaardtemperatuur Charge on electron e -1,6 x 10-19 C Lading op elektron Avogadro’s constant NA 6,02 x 1023 mol-1 Avogadro-konstante TABLE 2: FORMULAE/TABEL 2: FORMULES m N n n M NA n m V c OR/OF c n V MV VM c a Va na  pH = - log[H3O+] cb Vb nb Kw = [H3O+][OH-] = 1 x 10-14 at/by 298 K E θcell  E θcathode  E θanode / E sel  E katode   E anode or/of  Ecell  E θ reduction  E θ oxidation/ E sel  Ereduksie    E oksidasie or/of    sin g agent  E reducing agent / Esel  Eoksideermiddel  Ereduseermiddel θ θ θ E cell  E oxidi

Downloaded from hlayiso.com FISIESE WETENSKAPPE: CHEMIE 19 (VRAESTEL 2) GR12 0624 TABLE 3: THE PERIODIC TABLE OF ELEMENTS/TABEL 3: DIE PERIODIEKE TABEL VAN ELEMENTE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 (I) (II) (III) (IV) (V) (VI) (VII) (VIII) Atomic number/ KEY/SLEUTEL Atoomgetal 1 2 2,1 H He 1 29 4 Electro negativity/ Symbol/ 3 4 1,9 Cu 5 6 7 8 9 10 Li Be Elektronegatiwiteit Simbool B C N O F Ne 1,0 1,5 63,5 2,0 2,5 3,0 3,5 4,0 7 9 11 12 14 16 19 20 11 12 13 14 15 16 17 18 Na Mg Approximate relative atomic mass/ Aℓ Si P S Cℓ Ar 0,9 1,2 1,5 1,8 2,1 2,5 3,0 23 24 Benaderde relatiewe atoommassa 27 28 31 32 35,5 40 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 0,8 K 1,0 Ca 1,3 Sc 1,5 Ti 1,6 V 1,6 Cr 1,5 Mn 1,8 Fe 1,8 Co 1,8 Ni 1,9 Cu 1,6 Zn 1,6 Ga 1,8 Ge 2,0 As 2,4 Se 2,8 Br Kr 39 40 45 48 51 52 55 56 59 59 63,5 65 70 73 75 79 80 84 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 0,8 Rb 1,0 Sr 1,2 Y 1,4 Zr Nb 1,8 Mo 1,9 Tc 2,2 Ru 2,2 Rh 2,2 Pd 1,9 Ag 1,7 Cd 1,7 In 1,8 Sn 1,9 Sb 2,1 Te 2,5 I Xe 86 88 89 91 92 96 101 103 106 108 112 115 119 122 128 127 131 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tℓ Pb Bi Po At Rn 0,7 0,9 1,6 1,8 1,8 1,9 2,0 2,5 133 137 139 179 181 184 186 190 192 195 197 201 204 207 209 87 88 89 0,7 Fr 0,9 Ra Ac 226 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140 141 144 150 152 157 159 163 165 167 169 173 175 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232 238

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 20 (PAPER 2) GR12 0624 TABLE 4A: STANDARD REDUCTION POTENTIALS TABEL 4A: STANDAARD-REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V) F2(g) + 2e ⇌ 2F + 2,87 Co3+ + e ⇌ Co2+ + 1,81 H2O2 + 2H+ +2e ⇌ 2H2O + 1,77  MnO 4 + 8H+ + 5e ⇌ Mn2+ + 4H2O + 1,51   + 1,36 Cℓ2(g) + 2e ⇌ 2Cℓ 2 Cr2O 7 + 14H+ + 6e ⇌ 2Cr3+ + 7H2O + 1,33 O2(g) + 4H+ + 4e ⇌ 2H2O + 1,23 MnO2 + 4H+ + 2e ⇌ Mn2+ + 2H2O + 1,23 Pt2+ + 2e ⇌ Pt + 1,20 Br2(ℓ) + 2e ⇌ 2Br + 1,07  NO 3 + 4H+ + 3e ⇌ NO(g) + 2H2O + 0,96 Increasing reducing ability/Toenemende reduserende vermoë Hg2+ + 2e ⇌ Hg(ℓ) + 0,85 Ag+ + e ⇌ Ag + 0,80 Increasing oxidising ability/Toenemende oksiderende vermoë  NO 3 + 2H+ + e ⇌ NO2(g) + H2O + 0,80 Fe3+ + e ⇌ Fe2+ + 0,77 O2(g) + 2H+ + 2e ⇌ H2O2 + 0,68 I2 + 2e ⇌ 2I + 0,54 Cu+ + e ⇌ Cu + 0,52 SO2 + 4H+ + 4e ⇌ S + 2H2O + 0,45 2H2O + O2 + 4e ⇌ 4OH + 0,40 Cu2+ + 2e ⇌ Cu + 0,34 2 SO 4 + 4H+ + 2e ⇌ SO2(g) + 2H2O + 0,17 Cu2+ + e ⇌ Cu+ + 0,16 Sn4+ + 2e ⇌ Sn2+ + 0,15 S + 2H+ + 2e ⇌ H2S(g) + 0,14 2H+ + 2e ⇌ H2(g) 0,00 Fe3+ + 3e ⇌ Fe  0,06 Pb2+ + 2e ⇌ Pb  0,13 Sn2+ + 2e ⇌ Sn  0,14 Ni2+ + 2e ⇌ Ni  0,27 Co2+ + 2e ⇌ Co  0,28 Cd2+ + 2e ⇌ Cd  0,40 Cr3+ + e ⇌ Cr2+  0,41 Fe2+ + 2e ⇌ Fe  0,44 Cr3+ + 3e ⇌ Cr  0,74 Zn2+ + 2e ⇌ Zn  0,76 2H2O + 2e ⇌ H2(g) + 2OH  0,83 Cr2+ + 2e ⇌ Cr  0,91 Mn2+ + 2e ⇌ Mn  1,18 Aℓ3+ + 3e ⇌ Aℓ  1,66 Mg2+ + 2e ⇌ Mg  2,36 Na+ + e ⇌ Na  2,71 Ca2+ + 2e ⇌ Ca  2,87 Sr2+ + 2e ⇌ Sr  2,89 Ba2+ + 2e ⇌ Ba  2,90 Cs+ + e- ⇌ Cs – 2,92 K+ + e ⇌ K  2,93 Li+ + e ⇌ Li  3,05

Downloaded from hlayiso.com PHYSICAL SCIENCES: CHEMISTRY 21 (PAPER 2) GR12 0624 TABLE 4B: STANDARD REDUCTION POTENTIALS TABEL 4B: STANDAARD-REDUKSIEPOTENSIALE Half-reactions/Halfreaksies E θ (V) Li+ + e ⇌ Li  3,05 K+ + e ⇌ K  2,93 Cs+ + e ⇌ Cs  2,92 Ba2+ + 2e ⇌ Ba  2,90 Sr2+ + 2e ⇌ Sr  2,89 Ca2+ + 2e ⇌ Ca  2,87 Increasing reducing ability/Toenemende reduserende vermoë Na+ + e ⇌ Na  2,71 Mg2+ + 2e ⇌ Mg  2,36 Aℓ3+ + 3e ⇌ Aℓ  1,66 Increasing oxidising ability/Toenemende oksiderende vermoë Mn2+ + 2e ⇌ Mn  1,18 Cr2+ + 2e ⇌ Cr  0,91 2H2O + 2e ⇌ H2(g) + 2OH  0,83 Zn2+ + 2e ⇌ Zn  0,76 Cr3+ + 3e ⇌ Cr  0,74 Fe2+ + 2e ⇌ Fe  0,44 Cr3+ + e ⇌ Cr2+  0,41 Cd2+ + 2e ⇌ Cd  0,40 Co2+ + 2e ⇌ Co  0,28 Ni2+ + 2e ⇌ Ni  0,27 Sn2+ + 2e ⇌ Sn  0,14 Pb2+ + 2e ⇌ Pb  0,13 Fe3+ + 3e ⇌ Fe  0,06 2H+ + 2e ⇌ H2(g) 0,00 S + 2H+ + 2e ⇌ H2S(g) + 0,14 Sn4+ + 2e ⇌ Sn2+ + 0,15 Cu2+ + e ⇌ Cu+ + 0,16 2 SO 4 + 4H+ + 2e ⇌ SO2(g) + 2H2O + 0,17 Cu2+ + 2e ⇌ Cu + 0,34 2H2O + O2 + 4e ⇌ 4OH + 0,40 SO2 + 4H+ + 4e ⇌ S + 2H2O + 0,45 Cu+ + e ⇌ Cu + 0,52 I2 + 2e ⇌ 2I + 0,54 O2(g) + 2H+ + 2e ⇌ H2O2 + 0,68 Fe3+ + e ⇌ Fe2+ + 0,77  NO 3 + 2H+ + e ⇌ NO2(g) + H2O + 0,80 Ag+ + e ⇌ Ag + 0,80 Hg2+ + 2e ⇌ Hg(ℓ) + 0,85  NO 3 + 4H+ + 3e ⇌ NO(g) + 2H2O + 0,96   + 1,07 Br2(ℓ) + 2e ⇌ 2Br Pt2+ + 2 e ⇌ Pt + 1,20 MnO2 + 4H+ + 2e ⇌ Mn2+ + 2H2O + 1,23 O2(g) + 4H+ + 4e ⇌ 2H2O + 1,23 2 Cr2O 7 + 14H+ + 6e ⇌ 2Cr3+ + 7H2O + 1,33   + 1,36 Cℓ2(g) + 2e ⇌ 2Cℓ  MnO 4 + 8H+ + 5e ⇌ Mn2+ + 4H2O + 1,51 H2O2 + 2H+ +2 e ⇌ 2H2O + 1,77 Co3+ + e ⇌ Co2+ + 1,81 F2(g) + 2e ⇌ 2F + 2,87